Automatic air-feed control for rock drills



K w. A. SMITH.

AUTOMATIC AIR FEED CONTROL FOR ROCK DRILLS.

Patented Apr. 1s, 1922.

APPLICATION FILED FEB. `25. 1921.

x A# lNvENToR Y /ff ATTO EY .i 72,5 linen't', ifasoft spot is'enoountered,thepower Y To @ZZ/whom 'if mdg/ concerm y to' vbe held aj clainp,-a s' usually'v used for drilling substantially Ahorizoi'ital Vand down i WILLIAM AL SMITH, or PIIILLIPSBUEG,

Be itv knownithat I, YILLIAM'A.` SMITH, a citizen of tlieUnite d States, and aresident of Phillipsburg, county of Warren, State of New Jersey, h ave invented a certain AL1- This invention relates to fluid kpressure lrock drills of the hammer type, 'but.inore particularly to automa-tic air feed control for the feeding element,` whichV advances the machine. In' myy cao-.pending application,

. serialV v0.Y 447,757 una "February-25, i921, ,I have disclosed myautomaticlair feed conftrohapplied to a stopev drill' as an illustra# vtive example',while in' the presentjgapplicaitiOnjI have'disclose'd theinvention applied i.

to a so-c'alled drifter, OrYmachine.,adaptedv holes.

In operating lroolpdrilllof the'haminer ofthe air feed should ordina-rijlylloereduced, but .full rotation and hammeripowershould be retained, a or ifV possible, increased rotation should bei"produced',v to eijiabletheV machine to operate ingthemost lefficienti mannen -These changes fin the air lfeed control-have j heretofore beeneffecied hygiene to "Suit the accompanying drawings, Which-"- Y conditions of tliework, and oneiobjectf of the Y present ,inventionA is to venable'the air feeding element of a machineadapted to be held in a clamp, to beautomatically'controlled Another object is lto* effect the controlof such a type ofinachine by automatic ymeans responsive to the resistance to the rotation and the torquer of the rotation motor, forA au-v tomatically varying the pressure in theai'r feed cylinder of the feeding;element.,.jf

Toftheseand other ends,the invention is .illustrated in one ofits prefy vrred forms inthe Figure lY isa sidev elevation of a rock-drill embodying the invention, vpartly. inf longif tudinal section; i j f' Figure 2 is an enlargedr detail longitudinal sectional elevation through the feeding-'elelment j on the. line 2-2 of Figure 4L tlooking 'in the direction ofthe arrows; Y

Figure Sis a-detail longitudinal sectional the directioiiof the arrows; tornatic,AirfFeedControl, for RockDrills,

.of whichthe'following is aspecification. A Y the line 4-4 of Figure Y insteadsofclOSedpOSitiOn;V`V Y y A i Figure 6 vis a transversesectional viewV of 1 Figure Zion-the lined-6 lookingfinfthe difigure 7 -isa view ifi and froflthed BPrOvided.

vvtion sleeve `C throigli which the drill steel AD extendsfin positiontofreceive the impactf l blows of,` the. hammer 5,"A1'1findyep`gdet Iportion `Gr a and JERSEY; 'AssIGNOR To INGS'(EL RAND COMPANY, 0F JERSEY CITY, NEW 'JEEsEY,A CORPORATION or NEW l- S'pecication'of Letters Patent.' A .lfAlpiieationied lFebruar-W25, i921. I' y f Y semi No.. 447,758 v, j

Figure l 4c substantially` at right angles tothe plane on which Figure 2vistalien, looking in lFigure 4i' is Va transverse .sectional View on rection ofthe; arrows; 'Figure 5 is a View similar `to Figure 4 with the feed cylinderrelierf valve in'open 'rection Of-thejarrovvsyand ,v i similar' oFiguref-of a modification-ofthe cylinde y a ,leferring `,to-"the drawings,

2.' looking in the Adiview through feeding -felenient. I partly -Y broken away, and taken on-the line 3-'-3 of" unearned mais figures having a; Cylinder; e.

Afluidi actuated rotatiom motor 1 isf shownfin thi? insieme-@Freising ,ihr-drill stesura; .gafmoter heme mdicetediaving; the gears,

with the Yrota-V Qpistonrod J, operatiiigwithin thel feed cylin-Y @Gf isf,shownlocatedbetvveenjthe cylinder".v I i lder Kfo'f tlie-Qfeeding element. The rockA .Y l

Qdrillingfmachine isladapted to be'smounted v on Aand'connected ,to the tubular piston rod .J byranysuitable Vmeans (not shown), and

theparts are suitably held together fas .for f instance, by means of sidebolts (notshown). lnv accordance y with such( construction f the longitudinal movement of the piston rod in the 4feed cylinder K advancesthe machine to its work.

In this instance,-the `feedfcylinder shown :heldfwithin anyl suitable/and' usual Q foriniiig a closure for the front, end .ofthe Y i clamp `L and the feed cylinder' is provided '5 .with a: front head O, bushingl? and. stuffing 1,00'

cylinder *around the piston rod. Thepis'ton Y rod is provided rwitlia piston'R Ofany suitable or usual construction, and the rear'end Y of the feed cylinder K is provided with the baclrheadS fo-rininga closurev for the saine;v

VLThe tubularpistOn roddl'carries an i'iiterf nal guiding sleeve T having'a guide headlU provided with the ports V andlW, and this guiding vsleeve is guided 'on' a longitudinally stationary but rotatable guide rod X having a guide rod head Z suitably held within the feed cylinder bacl; head` S against the inwardly tapered bearing sleeve a. A sleeve Z) within the piston is provided with a spring c adapted to enter the tapered bore of the bearing sleeve a when the piston is retracted in order to hold the parts retracted when the machine is not in use. f The guide rod X is provided with a lon gitudinal groove (Z in which a key c within the sleeve b is seated so that the piston and piston rod are guided'longitudinally on the guide rod X and' any tendency of the drilling machine to rotate the tubular piston rod J and piston R will tend; to rotate the guide vrod X and guide rod head Z 'within the relatively fixed and non-rotatable feed cylinderk K.

Fluid pressure is supplied to the machine through the usual throttle valve' f and passes through the passage gto the tubular piston rodvJ. and thence through the port V in the head U on the guidingsleeveT and then passes'through' the` longitudinal groove h in the guide rod X to the rear of the piston R, thus forcing the piston outwardly in the feed cylinder l' for feedingpurpo'ses.

. ,The feed cylinder back head S, as shown,

is provided with a valve casing having a A valve 7c normally held inv closed position by means of the spring 0 beneath the cap p. The valve 7c controlsfthe passage Q communicating with theatinosphere atnthe atmospheric port r and serving to relieve the pressure behind the piston R when the valve Z is. open, 'as indicated in vligure 5, since the space behind the piston R is then in communication with' theV passage Vg through the porty a in thel guide rodliead Z. There is preferably sufficient clearance tj between the periphery of the guide rod head Zand the interior of the feed cylinder back` head Sto afford communication between the port s in the guide rod head Z and the passage Q in the valve casing Y The guide rod head Z is provided as shown with a cut away portion u adapted to bear upon the end c of the valve 7c.

-When the resistance to rotation of the drill steel is sufficient to cause relative rotary movement between the piston rod J,

pistorrR, guide rod VX, guide rod head Z, and the relativelyv stationary feed cylinder K, the valve 7c will be open to a greater or lesslextent, 'according to the movement of the guide rod head Z, thus automatically relieving the pressure in the air feed cylinder K in accordance with the requirements of the work. p I

In. order to retract the machine by air pressure at any time desired, a separate valve fw is mounted in the backv head S and controls the atmospheric port a3. A port y in the guide rod head Z affords communication between the longitudinal groove h in the guide rod X and a passage e in theguide rod head,r permitting the air to exhaust y through the guide rodA head'and through the interior of the valve w and valve port 3, to the atmosphere through the atmospheric port im when the valve w is turned to the l position indicated in Figure 3Q A suitable spring 4 within the guide rod head Z serves to maintain the valve w on its seat, and a suitable handle 5 may be provided for manually adjusting the valve fw; vThe air pa'ssing into the tubular piston J passes out through the port inthe guide rod head U, thence throughthe longit',udi'na'lv groove h and to atmosphere through the atmospheric port w, thus` relieving the pressure behind the piston R and permitting the pressure against the frontA of the piston head R through the ports 'lV in the head U ofthe guiding sleeve T toA retract the machine.y

ln the modification of the automatic air feed controlling valve shown in- Figure 7,

the waiveY casing jf is provided with a valve f d'havingV ay lhead 'subjectedfto' live air pressure through the passage- 7 and port'8 adapted 'toQbe connected with the inlet of the machine in any suitable manner so thatr the valveis mamtained'm closed position by fluid pressure instead of by a spring as shown 1n Figure 4, The space beneath;A the valve `head (Sis preferably vented to atmospliere at theport 9. kThe operation ofthe 'i device" indicated in VFigure 7 is otherwise thecombination with a drill" cylinder, of an,V

independent motor for rotating the drill steel, al fluid pressure feeding, elementfor feeding the machine forwardfcomprisin a stationary non-rotatable member, a rotata le and longitudinally movable member connected tothe drill cylinder, means for limiting the rotary movement of' said longitudinally movable member, means actuated by said rotary movement for automatically controlling the forward feeding of said feeding element' in accordance with the resistance to rotation, and additional means for controlling the return movement of said feeding element.

2. In a roclr drill of' the hammer type, the combination with a drill' cylinder, ofv an independent motor for rotating the drill steel, a fluidY pressure feeding element for feeding the machine forwa1-d'coinprising a stationary non-rotatable member, a rotatable and longitudinally movable member connected to the drillzcylinder,V means for limitingpthe rotary movement of said longitudinally movable member, a valve actuated by said rotary movement for automatically controlling the forward feeding of said feeding element in accorda-noe with the resistance to rotation, and an additional valye for controlling the return movement of said feeding element.

3. In a, rock drillof the hammerltype,

the combination with a drill cylinder', Yof an independent motor for rotating the drill Y steel, a iiuid pressure feeding element for feeding the .machine forward,` comprisingV a stationary non-rotatable cylinder, a guide longitudinally fixed relatively to theY feed cylinder, and having a limited rotary movement within the' feed cylinder, a piston yand hollow piston rod connected to the drill' cylinder' and longitudinal-ly movablegupon said guide but rotatable therewith, whereby suflcient resistance to rotation of the drill steel causes rotation of the guide and oon- Y nected parts in the feed cylinder, and means actuated by said rotary movement for au-l" tomatioally controlling `the forward feed of the machine.

4. In a rock drill of the hammer ltyv]j Je,K-the combination with adrill cylinder,-of an-in- 25v Vdependent motor for rotatingthe drill steel,

Y a fluid pressure feeding element for feeding 'Voient resistance to rotation ofthe drill steel causes rotation of the guide 'and connected parts in the l.feed Cylinder, and meansae- Y tuated by said` rotary movement for kau- 'v tomatically controlling-the forward feed of the machine, and additional means for con-` trolling lthe return movement of said 'feed ing element; f' l 5. In a rock drill of the hammer type, the combination 'with a drillv cylinder, of an independent motor for rotating the drillsteel,

a fluid pressure feeding element for feeding*v the machine forward,` comprisingv a stationaryV Vnon-rotatable jcylinder, a guide longitudinally fixed Vrelativelyto the feed cylinder, and having a limited rotary movekment within the feed cylinder, ahead on ysaid guide at the rearward end ofthe Vfeed cylinder, a piston and hollow piston rod con-4V nected totheV drill cylinder and longii jtudinally movableupon saidguide but rotai tableA therewithfa valve adaptedV toty be vac-v' A tuated bythe head on- .th'eprzsaidV guide for -V v eontrollinf-gf the fx'jrWL.,lfd feedingof-'the machine, wherebyy sufficient-resistance tol rotajtion of the drillsteel' causes "rotation of theV Vguide, and connected` parts.; andaactuatesthe said-. feed cylindercontrolling valve in ac-V Y Y cordance withrV the torque ofvrthe rotation f Ymotori? v l .Y

In testimony v'v'lhereofI` have signed'k this "j ii 'ff Y. 

